Cyclic a-Amino Acids via Enantioselective Metal-Catalyzed Cascade Reactions of Dienamides in Supercritical Carbon Dioxide

Highly enantioselective conversion of dienamides into cyclic a-amino acids can be achieved by a single-pot, tandem hydrogenation–hydroformylation–cyclization–elimination sequence using a single catalyst and supercritical carbon dioxide (scCO2) as the reaction solvent at total pressures significantly lower than those previously reported for related hydrogenation and hydroformylation reactions.